Process for the preparation of vinyl chloride graft polymers

ABSTRACT

A process for the preparation of a vinyl chloride polymer composition, which comprises (a) dissolving an oil-soluble polyalkylene oxide such as polypropylene oxide, or a copolymer of propylene oxide in the 1-butene oxide or epichlorohydrin, in a monomeric mixture consisting of 99.5 - 90 parts of a vinyl chloride monomer and 0.5 - 10 parts of a comonomer such as ethylene, propylene or 1-butene, the amount of said oil-soluble polyalkylene oxide being 0.5 - 5 percent by weight based on the monomeric mixture, (b) emulsifying or suspending the resulting solution in water, (c) polymerizing the emulsified or suspended solution and (d) recovering the resulting polymer composition. The vinyl chloride polymer composition obtained has very high impact strength even at low temperatures, and same good transparency and other physical properties as polyvinyl chloride.

Nakano et al.

3,725,507 Apr. 3,1973

PROCESS FOR THE PREPARATION OF VINYL CHLORIDE GRAFT POLYMERS Inventors:Satoshi Nairano; Keiichi Azurna; Seiichiro Oba; Samon wt-mun; SuniehiNakamura, all of Tokuyama, Japan Assignees: Tokuyama Soda KabushikiKaisha; Sun Arrow Chemical Co., Ltd., Yomaguchi-ken, Japan; partinterest to each Filed: Oct. 27, 1971 Appl. No; 192,895

Related U.S. Application Data Continuation-impart of Ser. No. 878,948,Nov. 21, 1969, abandoned.

Foreign Application Priority Data Nov. 26, 1968 Japan ....43 /8 6083U.S. Cl. ..260/896, 260/285 D, 26 0/897 C,

' I 260/899 Int. Cl. ....C08f 37/18, C088 29/24 Field of Search..260/896,897, 899

[56] Reierences Cited UNITED STATES PATENTS 3 147,291 4/1966 Kahrs..260/899 Primary Examin'erSamu el H. Blech Assistant Examiner-C. .l.Seccuro Attorney-Leonard W. Sherman et al.

57 ABSTRACT A process for the preparation of a vinyl chloride polymercomposition, which comprises (a) dissolving an oil-soluble polyalkyleneoxide such as polypropylene oxide, or a copolymer of propylene oxide inthe i-butene oxide or epichlorohydrin, in a monomeric mixture consistingof 99.5 90 parts of a vinyl chioride'monomer and 0.5 l0vparts ofvacomonomer such as ethylene, propylene or l-butene, the amount of saidoil-soluble polyalkylene oxide being 0.5 5 percent by weight based onthe monomeric mixture, (b) emulsifying 0r suspending the resultingsolution in water, (c) polymerizing the emulsified or suspended solutionand (d) recovering the resulting polymer composition. The vinyl chloridepolymer composition obtained has very high impact strength even atlow'temperatures, and same good transparency and other physicaiproperties as polyvinyl chloride.

4 Claims, 4 Drawing Figures PATENTEUAPRZ? ms SHEET 1 BF 4 h 5 w 2 m 5 O5 V Fig.

E S IGzwEm SE2.

[1] OF POLYALKYLENE 0x105 PATENTEUAPR3 ms SHEET 2 [IF 4 Fig. 2

['1] OF POLYALKYLENE OXIDE PATENTEDAPR3 I975 SHEET 3 [IF 4 Fig. 3

Ikwzwmkm .GAES:

[1] OF POLYALKYLENE OXIDE PATENTFUAPM I975 SHEET [1F 4 22 IGzwEm O 5 6r3 v q wimzm;

2 9; 157mm; SE5;

AMOUNT OF PROPYLENE IN MONOMERI MIXTURE BY WEIGHT) PROCESS FOR THEPREPARATION OF VINYL CHLORIDE GRAFT POLYMERS This application is acontinuation-in-part application of the application Ser. No. 878,948file on Nov. 21,

1969, which has now been abandoned.

This invention relates to a process for the preparation of a vinylchloride polymer composition having an improved impact strength. Moreparticularly, the inv vention relates-to a process for the preparationof a vinyl chloride graft polymer of an excellent impact strength, whichcomprises dissolving an oil-soluble alkylene oxide polymer in amonomeric mixture of vinyl chloride and an a-olefin monomer, andpolymerizing said monomeric mixture.

Polyvinyl chloride has heretofore found wide utility as a low costsynthetic resin in film, sheet and other shaped products. It has alsobeen practised to copolymerize monomeric vinyl chloride with vinylacetate, vinyl ether, a-olefins, etc., to provide vinyl chloridepolymers of good workability as well as high transperency. However,vinyl chloride polymers, in general, have a defect that the impactstrength is low. This defect is particularly conspicuous with a vinylchloride polymer of a low degree of polymerization exhibiting goodworkability, e.g., of .the degree of polymerization ranging from 600 to800. This defect has not allowed the full utilization of variousexcellent properties of polyvinyl chloride in many fields. For example,polyvinyl chloride is not widely used in the field of architecture,because construction materials such as sheet, bolt, bottle, pipe,combination joint, and window cordingly, improvement in the impactstrength in I polyvinylchloride is an important research problem,

and various proposals have already been made. For example, it isknown toblend polyvinyl chloride with polymers having a low glass transitiontemperature, such as an acrylonitrile/butadiene/styrene copolymer and anethylene/vinyl acetate copolymer, or to blend polyvinyl chloride withchlorinated polyethylene. Also there has been proposed a process inwhich polyvinyl chloride is grafted to a copolymer such as mentionedabove. However, in these known methods it is generally necessary to uselarge amounts of such impact strengthimproving components to be blendedor graftpolymerized with polyvinyl chloride, in order to achievesatisfactory results. Since such impact strength-improving agents arerather expensive as compared with polyvinyl chloride and required to beused in large quantities, these known methods are unsatisfactory fromthe economical viewpoint. Further, in many cases the improvement in theimpact strength is achieved at the cost of transparency of the productwhich is one of favorable properties of polyvinyl chloride. Conversely,attempts to retain the high transparency of polyvinyl chloride result ininsufficiency of the improvement in impact strength.

Accordingly, an object of this invention is to provide a vinyl chloridepolymer composition having a sufficiently improved impact strength withadvantageous properties inherent to polyvinyl chloride being fully framerequire a high level of impact strength. Ac- 1 Still another object ofthe invention is to provide a vinyl chloride graft polymer having anexcellent impact strength without impairing the transparency inherentlypossessed by polyvinyl chloride.

A still further object of the invention is to provide a 3 oxide,poly-l-butene oxide, a copolymer of propylene oxide and l'butene oxideand a copolymer of an al- I kylene oxide selected from propylene oxideand l-butene oxide with epichlorohydrin, in a monomeric mixtureconsisting of 99.5 90 parts of a vinyl chloride monomer and 0.5 10 partsof a comonomer selected from the group consisting of ethylene,propylene, l-butene and iso-butene compounds, the amount of saidoilsoluble polyalkylene oxide being 0.5 5 percent by weight based on themonomeric mixture, (b) emulsifying or suspending the resulting solutionin water, (c) polymerizing the emulsified or suspended solution at atemperature of 30 C. in the presence of.0.01 5

percent by weight, based on the monomeric mixture, of v a radicalpolymerization catalyst, and (d) recovering the resulting polymer.

According to this invention, at first (i) an oil-soluble polyalkyleneoxide selected from the group consisting of polypropylene oxide,poly-l-butene oxide, 1 a copolymer of propylene oxide and l-butene oxideand a copolymer of an alkylene oxide selected from propylene oxide andl-butene oxide with epichlorohydrin (which will be referred to asoil-soluble polyalkylene oxide hereinbelow) is dissolved in (ii) amonomeric mixture consisting of 99.5 parts of a vinyl chloride monomerand 0.5 10 parts of a comonomer selected from the group consisting ofethylene, propylene, l-butene and iso-butene compounds, the amount ofsaid oil-soluble polyalkylene oxide (i) being 0.5 5 percent by weightbased on said monomeric mixture (ii).

Thus, in this invention it is essentialto dissolve the oil-solublepolyalkylene oxide in the monomeric mixture comprising a vinyl chloridemonomer and an aolef'm monomer in advance of the polymerization of themonomeric mixture. That is, the polyalkylene oxide to be used in theinvention must be soluble in the chloride monomer, such as polyethyleneoxide and polyisobutylene oxide. The former polymer is soluble in waterand the latter polymer is crystalline. Since the increase of thecrystallinity in polyalkylene oxides tends to impair the transparency ofthe vinyl chloride graft polymer of the invention, optimum results arenormally obtained by the use of an amorphous oil-soluble polyalkyleneoxide containing substantially no crystalline portion.

The oil-soluble polyalkylene oxide to be used in this invention has anintrinsic viscosity [1 measured in benzene at 35C., of from 1.3 to 4.5.When the molecular weight of the oil-soluble polyalkylene oxide isexcessively high, the viscositybf a solution formed by dissolving thepolymer in the monomeric mixture containing a vinyl chloride monomertends to rise noticeably,

which is disadvantageous for the subsequent operation of polymerizingthe monomeric mixture. In contrast, if

the molecular weight is too low, a sufficient degree of oil-solublepolyalkylene oxide and the impact strength of the resulting vinylchloride polymer composition. In order for the oil-soluble polyalkyleneoxide to be readily soluble insaid vinyl chloride monomer-containingmonomeric mixture while giving a solution excellent in workability andto impart a highly improved impact strength to the resulting polymercomposition, the oilsoluble 'polyalkylene oxide should have an intrinsicviscosity, measured in benzene at 35C., of from 1.3 to

4.5,preferably 1.5 to 4.0.

The oil-soluble polyalkylene oxide is dissolved in the vinyl chloridemonomer-containing monomeric mixture in an amount of 0.5 to 5 percent byweight, preferably 1.0 to, 3.5 percent by weight, based on the monomericmixture. When the oil-soluble polyalkylene oxide is added in an amountsmaller than the lower limit of the above range, the resulting vinylchloride polymer composition exhibits still an insufficient impactstrength. On the other hand, in case the amount of the oil-solublepolyalkylene oxide exceeds the upper limit, physical properties other Ithan the impact strength of the resulting polymer composition, forexample, tensile strength transparency are degraded, though asatisfactory improvement in the impact strength may be achieved.

The manner of the preparation of the above-mentioned oil-solublepolyalkylene oxide is not critical, but products of polymerization orcopolymerization of the above-mentioned alkylene oxide monomer ormonomers are generally used. For example,'polymers or copolymers formedby ring-opening polymerization of the alkylene oxide monomer or monomerscan be used as they are. Further, mastication products of high molecularweight polyalkylene oxides formed by using such means as roll milling,or polycondensation products of corresponding polyalkylene glycols maybe dissolved in such monomeric mixture is that a polymer compositionobtained by dissolving the oil-soluble polyalkylene oxide (i) into themonomeric mixture (ii) consisting of 99.5 90 parts of the vinyl chloridemonomer (iii) and 0.5 10 parts ofthe a-olefm comonomer (iv) and graftpolymerizing the monomeric mixture (ii) to the oil-soluble polyalkyleneoxide (i) is' superior in the impact strength, transparency andworkability to a polymer composition obtained by'dissolving theoil-soluble polyalkylene oxide (i) into a vinyl chloride monomer andpolymerizing vinyl chloride thereto. I

As a result of our research it has been found that the amount of thea-olefin comonomer contained in said' monomeric mixture is closelyconcerned with thephysical properties of the polymer compositionobtained by graft polymerization. More specifically, when" the a-olet'mcomonomer is added to the vinyl chloride comonomer in a smaller amount,for instance, 0.5 percent by weight, preferably 2 percent by weight,based on the monomeric mixture, the impact strength of the resultingpolymer composition increases abruptly, and at the same time the tensilestrength, transparency and workability thereof are improved. Suchimprovement in the physical properties is conspicuous when the aolefinis incorporated in an amount of 5 6 percent by weight based on themonomeric mixture. l-lowever, at a greater proportion of the q-olefin inthe monomeric mixture, either the impact strength or, tensile strengthtends to be lowered, and when the proportion of the acompositiondecreases considerably and the tensile strength is lowered as well.

In view of the foregoing, in accordance with this-invention, theoil-soluble polyalkylene oxide is dissolved into a monomeric mixtureconsisting of 99.5 .90 parts by weight, preferably 98 91 parts byweight, of a vinyl monomer and 0.5 10 parts by weight, preferably 2- 9parts by weight, of the above-mentioned a-olefin comonomer, and the saidmonomeric mixture is then graft-polymerized. I e

In case ethylene or propylene is used as said'comonomer, since suchcomonomer is ordinary in the gas form, it is operationally difficult orimpossible to prepare in advances mixture of such comonomer with vinylchloride which is in the liquid state at room temperature andatmospheric pressure. In such case, the oil--soluble polyalkylene oxideis dissolved in the vinyl chloride monomer, and when thesuspension oremulsion polymerization of the resulting solution is conducted underconditions described "below, such normally gaseous comonomer as ethyleneor propylene is fed continuously'or at a time to the polymerizationvessel .(polymerizationsystem) and it is polymerized together with thevinyl chloride monomer. Even .such feature is included in the monomericmixture of the vinyl chloride monomer and comonomer of the presentinvention. The reason is that the a-olefin comonomerknown emulsion andsuspension polymerization techniques employing a radical initiator maybe adopted. Further, known techniques of controlling the ratios ofcomponents to be copolymerized, the distribution of the molecularfraction of the product polymer and the molecular weight of the product,etc. may be optionally adopted during the polymerization. For example,in the emulsion polymerization 0.01 5 percent by weight, based on themonomeric mixture, of a 1 water-soluble radical catalyst such aspersulfates e.g., I

potassium v persulfate and ammonium persulfate, hydrogen peroxide andthe like may be made present together with an emulsifier such as knowncationic, anionic and nonionic surface active agents, in the aqueouspolymerization system comprising the monomeric mixture. The suspensionpolymerization may be practised in an aqueous polymerization system inthe presence of 0.01 5 percent by weight, based on the monomericmixture, of an oil-soluble radical catalyst, for example, peroxides suchas lauroyl peroxide and benzoyl peroxide, azo'compounds such asazobisisobu tyronitrile, and diisopropyl peroxycarbonate and tert.-butyl perpivarate, and also in the presence of an appropriate amount ofa suspension polymerization stabilizer such as methyl cellulose,hydroxyalkyl cellulose, polyvinyl alcohol, and polyvinyl pyrrolidone.Suitable temperatures for these polymerization operations differdepending on types of a-olefin comonomers to be used,

but generally, the polymerization is conducted at temperatures rangingfrom 30 to 80C., preferably 40 to 70C.

Furthermore, the suspension or emulsion polymerization techniquesdisclosed, for example, in Chemical Engineering, 74 PP 151 158 (1967),ibid, 74 (14), pp 85 92 (1967), etc., may be applied to thepolymerization of the monomeric mixture.

lt possible to blend the resulting vinyl chloride polymerv compositionof the invention with any of known impact strength-improving agents,such-as an acrylonitrile/butadiene/styrene copolymer, a methylmethacrylate/butadiene/styrene copolymer, and an acrylonitrile/rnethylmethacrylate/butadiene/styrene copolymer. For instance, a polymercomposition having an excellent impact strength while retaining afavorable transparency can be obtained by blending 1- 10 parts of such'impact strength-improving agent into 99' 4 90iparts of the vinylchloride polymer composition of the invention.

The vinyl chloride polymer composition obtained in accordance with thepresent invention has a prominently high impact strength. Furthermore,the impact strength can be advantageously maintained at a satisfactorilyhigh level even under'low temperature conditions. Also in the vinylchloride polymer composition of this invention, favorable propertiesinherent to polyvinyl chloride such as transparency and other physicalproperties, are not impaired. In fact, it is apparent from experimentalresults shown in Examples given below that. the vinyl chloride polymercomposition of the invention is entirely different from a simple mixtureof a vinyl chloride polymer with an oil-soluble polyalkylene oxide. Thatis, the composition of the invention exhibits a highly improved impactstrength over such simple mixture. Accordingly, the vinyl chloridepolymer composition of the invention can be advantageously used in manyfields where full utilization of polyvinyl chloride resins has beenprevented because of their insufficient impact strength.

The present invention will ,now be detailed by referring to Examples andComparative Examples, but. the scope of the invention is in no waylimited by these Examples. Values of the physical properties given inthe Examples are those measured as to sheets formed under blending andshaping conditions specified in Tables A and B given below, through rollmilling and pressing steps. The transparency, the degree ofpolymerization, and the impact-strength were deter mined in the mannersdescribed below unless otherwise specified. Percentile ratios and partsare on the weight basis unless otherwise specified.

Blending and sheet-forming conditions: (i) Recipe for hard andtransparent product TABLE A Vinyl chloride polymer composition to betested 100 parts Dibutyltin maleate 2 parts Dibutyltin laurate 2 partsDi-tert.-butyl-p-cresol 0.2 part Rolling conditions: milling at 155C.for

10 minutes pressing at 175C. under 70 kglcm' for. 16 minutes TABLE BVinyl chloride polymer composition to be tested 100 parts Dioctyltinmaleate 3 parts Dibutyltin maleate 1.5 parts BISUAMIDE' 0.3 part KASUTAwax 0.3 part Pressing conditions:

' Measurementof transparency:

The percent transmission of light of 550m i n:wave length through thetest piece of 1 mm in thickness was measured with a double-beamspectrophotometer, based on the percent transmission of the lightthrough air as 100. The percent transmission of the light may bereferred to simply as percent transmission" hereinafter.

Measurement of degree of polymerization:

The measurement is conducted according to the method of 118 K 6721. Whenthe solution viscosityof the polyalkylene oxide is greater than that ofpolyvinyl chloride, the apparent degree of polymerization is very high.Accordingly, in the Examples the pro perty is indicated as the apparentdegree of polymerization.

Measurement of intrinsic viscosity:

The sample is dissolved in benzene, andvalues of the relative viscosity(1 rel) at various concentrations are measured at 35C. The intrinsicviscosity [1 (lim 1 rel) to zero. Measurement of impact strength:

A sample sheet of 0.55 i- 0.03 mm in thickness and 12 mm X 12 mm in sizewas subjected to Du Pont impact tester (impact needle size A inch) at 25i 03C. At each level of potential energy of a falling hammer, 20 sheetsof the sample are given a shock, and their breaking ratios are plottedon a logarithmic normal distribution graph, to calculate the energylevel at which 50 percent the testsheets are broken, said energy levelbeiriggiven as impact strength. The impact strength will be abbreviatedas IS in the Examples. Measurement of flow temperature:

rel/c) was calculated by extrapolating the value of (1;

blended with the polyalkylene oxide, a major portion of the polyalkyleneoxide is isolated in Fraction 3, and therefore, Fraction-3 has a verylow CI content.

By the above-mentioned method, it is confirmed that in the vinylchloride polymer composition obtained in accordance with this inventionthe copolymer of vinyl The flow temperature of the sample composition isI be abbreviates as TS in the Examples.

Confirmation of vinyl chloride graft polymers:

The vinylchloride polymer composition obtained in the present inventionis roll-kneaded according to the recipe of a hard and transparentproduct, and then it is press-molded. The so formed sheet isfractionated by the following procedure and the confirmation is effectedby the elementary analysis.

Fraction 1:

The sheet is dissolved in 30 g of tetrahydrofuran capable of dissolvingboth the polyvinyl chloride and polyalkylene oxide. The precipitateformed by addition of 350 cc of benzene under stirring is separated anddried under reduced pressure.

Fraction 2:

' The remaining mother liquor is concentrated untilits amount is reducedto 60 cc. The resulting precipitate is separated and dried under reducedpressure. Fraction 3: The remaining mother liquor is dried under reducedpressure.

Fraction 3 should naturally consist of the polyalkylene oxide, thecopolymer of vinyl chloride with an a-olefin comonomer having alowmolecular weight, and the stabilizer and lubricant added at the time ofmaking the sheet, which have been all readily soluble in benzene. If theobtained vinyl chloride polymer composition is grafted, the polyalkyleneoxide is coprecipitated in any of the above fractions in equal ratiosaccording to the molecular weight of the grafted copolymer of vinylchloride and the a-olefin comonomer. Hence, the elementary analysis ofeach of the Fractions shows that the Cl content of each fraction isalmost equal to one another. It can be confirmed that the polyalkyleneoxide is grafted, since it is not isolated by the fractionalprecipitation.

On the other hand, when the copolymer of vinyl chloride and the a-olefinV comonomer is merely chloride and the a-olefin comonomer is grafted tothe oil-soluble polyalkylene oxide. I

The abbreviations used in the Examples have the following meanings:

FAQ polyalkylene oxide VCM vinyl chloride monomer Lll tert.-butylperpivarate LOP lauroyl peroxide AIBN azobisisobutyronitrile [1;]intrinsic viscosity of polyalkylene oxide PPO polypropylene oxide PBOpolybutene-l ,2-oxide VA vinyl acetate PO propylene oxide BO l-buteneoxide ECH epichlorohydrin Pr propylene Et ethylene l-But: l-butene i-Butisobutene EXAMPLE 1 A 5-liter capacity polymerization vessel equippedwith a stirrer was charged with polypropylene oxide in an amountindicated in Table 1 together with 200 parts of pure water, 0.01 part of"Liponox NCA (commcr- I cial polyoxyethylene nonyl phenyl ethermanufactured by Lion Y-ushi l (.K.) and with Methocell 90 SH I00"(commercial methyl cellulose manufactured by The Dow Chemical Co., whichwill be abbreviated as MS" hereinbelow) in an amount of 0.05 part in RunNo. 1, 0.07 part in Run No. 2 or 0.10 part in Runs Nos. 3 through 10.The inside atmosphere of the vessel was replaced by nitrogen, and theinside pressure of the vessel was reduced to mm Hg with a vacuum pump,into which vinyl chloride and propylene were fed in amounts indicated inTable 1, followed by 8 hours stir: ring at 40C. to dissolve thepolypropylene oxide in the monomeric mixtureof vinyl chloride andpropylene;

transparent product shown in Table B above, rollmilled and pressed intoa sheet. The test results of the sheets are given in Table l, and valuesof the impact strength in Runs Nos. 5 to 10 are plotted in curve I) ofFIG].

In case the amount of VCM is indicated doubly (for example, Run No. 2 inTable l) the upper amount is one caused to be initially present in thepolymerization system and the lower amount is one supplied to thepolymerization vessel at a'rate of seven parts per hour by means of aplunger pump during the polymerization.

7 H w m I TABLE w Run Number 1 2 3 4 5 (i 7 S l) 10 FAQ:

I pe PPO PPO FPO PPO PPO PPO PPO .PPO PPO PPO [1, (dL/gr.) 2.1 2.1 2.12.1 0.5 1.5 2.1 3.0 4.0 5.0 Amount (parts) 1.0 2.0 3.0 3.5 2.0 2.0 2.02.0 2.0 2.0 vcM: Amount (parts) 94.5 22:2 94.5 94.5 95.0 95.0 95.0 95.095.0 95.0 Comonomer: I

'Iy Pr Pr Pr Pr Pr Pr Pr Pr Pr Pr C amount (parts) 5.5 5.5 5.5 5.5 5.05.0 5.0 5.0 5.0 5.0

Ty LII LII LII LII LII LII LII LII LII LII Amount (parts) 0.12 0.12 0.120.12 0.12 0.12 0 12 0.12 0.12 0.12 Polymerization:

Temperature C 60 49. 5 50 62 50 50 50 50 50 60 Time (hr.:m1n.). 22:0022:00 22:00 22:00 :00 20:00 20:00 20:00 20=00 20:00 Yield (percent) 81.8 78. 4 78. 7 85. 4 78. 5 80. 4 79. 2 33., 1 80. 4 31. 2 Apparent degreeof polymerization 892 900 986 903 786 844 820 892 923 992 Proper les ofmolded sheet:

TS (kgJm 5.5 5.4 5.0 4.9 5.3 5.4 5.4 5.3 5.3 5.4 Is (kg.-crn.) 9. 0 3240 5. 2 18. 5 32. 0 33.1 31. 5 30. 4 Pereenttransml to 82.9 79.5 74.350.4 78.2 79.4 80.0 79.4 79.5 73.5 110 157.8 155.5 155.1 152.5 155.2165.8 155.4 155.9 158.1 159.5 Gear oven stability (mln.) 125 130 130 105130 125 130 130 125 125 CQMP'ARATTVE EXAMPLE 1 copolymer of Kim No. l of2.5 2.0 19

Comparative Example 1 For comparison, experiments of Example I were re-20 PVC (PT-802) peated without employing any polyalkylene oxide. TheEXAMPLE 3 polymerization was conducted under conditions indicated inTable 2. Runs Nos. 2, 4 and 8 were perun N0. 1 of Example 1 was repeatedby employing formed similarly to Run No. 2 of Example 1. Results partsof a pr py oxide/epichlorohydrin are shown in Table 2. copolymercontaining 4 mole percent of 4 515914 2. 4 mm Results Comonomer CatalystPolymerization condition Apparent degree of Percent Amount AmountTempera- Time Yield polymeri- IS TS Ti trans- (parts) Type (part) tu1'e(C.) (hr.:1nin.) (percent) zation (kg/cm.) (kg./mm 0.) mission EXAMPLE 2The experiment of Run No. 3 of Example I (see Table l) was repeated tosynthesize a vinyl chloride graft polymer, by employing a polypropyleneoxide having an intrinsic viscosity of 3.3. The resulting vinyl chloridegraft'polymer composition was blended in accordance with the recipeshown in Table B, rollmilled, pressed and laminated into a sheet of 12mm in thickness, which was then formed into a sample to be subjected tothe Izod impact test.

For comparison, the vinyl chloride/propylene copolymer obtained in RunNo. l of Comparative Example 1 (see Table 2) and polyvinyl chloridehaving a degree of polymerization (i of 800 were separately formed intosimilar samples, and their Izod impact strength was determined. Resultsare shown in Table 3.

The temperature at which the Izod impact strength was measured isindicated in Table 3. The determination of the Izod impact strength wasconducted in accordance with ASTM D-256 in all cases.

I obtained in Example 2 epichlorohydrin and having an intrinsicviscosity [1;] of 2.3 instead of 1 part of the polypropylene oxidehaving an intrinsic viscosity [1;] of 2.1. The copolymer was dis--'solved in a monomeric mixture composedof 94.5 parts of vinyl chlorideand 5.5 parts of propylene, and the EXAMPLE 4 The experiment of Run No.2 of Example 1 was repeated by employing acopolymer indicated in Table 4instead of the polypropylene oxide used in Example 1. The amount ofvinyl chloride added initially to the polymerization system correspondsto the amount (parts) obtained by subtracting the sum of the amount ofvinyl chloride additionally fed during the polymerization and the amountof propylene from I00 parts. In each Run the polymerization temperaturewas changed as indicated in Table 4 during the polymerization.

11 12 v TKBLEI EXAMPLES gxb 1 2 A 2 -li ter capacityautoclave eduippedwitha stirrer Typc P030 0430 was charged with vinyl chloride andpolypropylene l 5 5 5 oxide in amounts indicated in Table 6. The [11]2.7 2.0 Amount (parts) [.5 L5 polypropylene oxide was dissolved in thevinyl chloride by conducting the agitation at room temperature for 4Cemonemer. V I Amoum (Pam) 2' g3 Separately, a 5-liter capacityautoclave equipped Amount of Additionally Fed VCM (parts) 30.2 35.0 witha stirrer was charged with 200 parts of pure water,

0.5 part of polyvinyl alcohol and a polymerization in- Catalyst itiatingcatalyst in an amount indicated in Table 6. K After the insideatmosphere had been replaced by mount (part) 0.12 0.12

nitrogen, the inside pressure of the autoclave was PolymerizationConditions l5 reduced to mm Hg, into which the total of the solu-Temperature ('C.) 4 ,0 49,0 tion prepared above was supplied. Then,ethylene in an Time (hr) fi i3 amount indicated in Table 6 was chargedinto the au- 5 5 toclave. The reaction mixture was stirred and heated toa temperature indicated in Table 6 to accomplish the Results 20polymerization. After completion of the polymeriza- Yield tion,unreacted monomers were purged, and the slurry g agi'gf pdymmmm 232 :23;was withdrawn, filtered and dried to obtain a vinyl fi i 7 5.65chloride-ethylene graft polymer as a white powder. The .0 1 6.2 Percentmmmiuion (9b) a powdery polymer was shaped into a sheet by adopting 25the recipe for the modified, hard and transparent product indicated inTable B, and the physical properties thereof were determined to obtainresults shown in EXAMPLE 5 Table 6. The values of the impact strength ofsamples The experiment f Run 2 f Example 1 was of Runs Nos. 1 to 6 wereplotted to form curve a in FIG. peated by employing a copolymer ofpropylene oxide V H W l H with l,2-butene oxide or epichlorohydrininstead of the In conducting Run No. 7 of this Example, there waspolypropylene oxide in Example 1 and varying the kind adopted the samemethod as employed in Example 1, and amount of the a-olefin as indicatedin Table 5. In except that 0.07 part of MS was charged and the Run No. 1the temperature was changed during the 3s ethylene was fed after'theaddition of the catalyst, and polymerization as indicated in Table 5.that the polymerization was practised under purging of The results areshown in Table 5, and the values of ethylene at a suitable rate tomaintain the inside presthe impact strength of samples of Runs Nos. 1 to3 and sure of the autoclave at a level not higher than 20 5 to 7 areshown in curve e in FIG. 2 and curve f in FIG. kg/cm', because theinside pressure rose with the ad- 3. 4o vance of the polymerization.

TABLE .5

Run number 1 2 3 4 5 6 7 8 9 FAQ:

T e PO-BO PO-BO PO-BO PO-BO PO-ECH PO-ECH PO-ECH PO-ECH PO-BO yp 95/5 955 95 5 30 96/4 96/4 /4 90/10 /5 [11] (dL/gr.) .7 3.1 .0 0.5 2.3 3.7 2.12.0 Amount (parts) 8 8 VCM (Parts) 2s: 0 2810 23: 0 as: o Comonomer:

Type Pr lr lr l-But Pr Pr lr Pr Pr Amount (parts) 5. 5 5. 5 5. 5 6. 0 6.0 6. O 6. 0 5. 5 5. 5 Catalyst:

Typo ml Lil LII Lll Lil Lll LH 11 on Amount (part) 0.12 0. l2 0. l2 0.12 0. l2 0. l2 0. l2 0. 12 U. 12 Polymerization conditions:

p atu 3:8 ,313 Time (hr.:min.) Egg, 2g Polymerization results:

Yield (percent) 83. 3 8;. (l 81. .2 Apparent degree oi polymerizationsee 906 892 Properties of molded she TS (kgJmmJ)... 5. 7 5. ii 5. 5(kg.-cm.) 6. 3 17.0 16. 8 Percent transmissien 80. 6 82. l 82. 1 '1: 0.164.5 165.0 166. 2 Gear oven stability (min.) 130 125 TAB LE 7 TABLE 6Run Number 1 2 3 4 5 6 7 FAQ:

Type PPO PPO PPO PPO PPO PPO PPo 1] (dL/gr.) 0. 5 1.6 2.1 3. 3. 9 5. o2. 1 Amount (parts). 2. 0 2. 0 2. 0 2. 0 2. 0 2. 0 2. 0 VCM: Amount(part 98. 2 98. 2 98. 2 98. 2 98. 2 98.2 90.0 Comouomer:

Type Et Et Et Et Et Et Et Amount (parts) 1. 8 l. 8 1. 8 1. 8 1. 8 1. 810. 0 atalyst:

LII LII LII LII LII LII LII Type I6PO LPO LPO mo LPo LPo 06 0. 06 0. 060. 0 0. 0 0. 0 0. 2 Ammm (Pm) 0. 04 0. 04 0. 04 o. 04 o. 04 0. 04Polymerization conditions:

Temperature C.) 54 54 54 54 54 49. 5 Time (hr.:min.) 10:00 10:00 10:0010:00 10:00 10:00 18:00 Polymerization results: 1 Yield (percent) 81.278. 7 .5 7s. 5 77. 3 78.6 Apparent degree of polymerization 1, 274 1,331 1, 325 1, 329 1, 340 1, 372 875 Properties of molded sheet:

TS (kgJmmfl) 5. 3 5. 5 5. 4 5. 5 5. 4 5. 5 5. 1 IS (kg.cm.) 9- 5 19 3436 36 33 24 Percent transmission 60- 3 66. 2 68. 4 67.5 67. 7 66. 5 82.1 Ti C.) 172. 1 173. 3 174. 6 174. 2 175. 5 176. 9 134. 2 Gear ovenstability (min.) 130 125 130 130 125 130 125 EXAMPLE 7 20polyoxyethylene stearate. The resulting emulsion was salted out byaddition of saturated saline water, followed by filtration and drying.Thus there was obtained a graft copolymer having an apparent degree ofpolymerization of 1023 in a yield of 82.1 percent. The copolymer wasshaped into a sheet in the samernanner as in Example 1, and theproperties of the sheet were determined to obtain the following resultsa percent transmission of 69.5 percent, IS of 31 kg-cm and TS of 4.5kg/mm'.

Run number 1 2 3 4 5 6 7 FAQ:

'1 pe PPO PPO PPO PIO PPO PIO PPO Amount (parts) 1.5 1.5 1.5 1.5 1.5 1.52.0 VCM: Amount (parts) 94. o 04. 0 114.0 114. 0 114. 0 s4. 0 iii-gComonomer:

Amount (parts) 6.0 6. 0 6.0 6. 0 6.0 6. 0 6.0 Catalyst:

Type LII LII LII LII LII LII LII Amount (part) 0. 0.15 0. l5 0. l5 0. l50. 15 0. 15 Polymerization conditions:

Temperature C.) 48 48 48 48 48 48 47.5

Time (h1'.:min.). :00 20:00 20:00 20:00 20:00 20:00 22:00 Polymerizationresults:

Yield (percent) 79. 3 80. 2 78. 4 78. 6 79. 5 77. 3 78. 2

Apparent degree of polymerization... 820 803 016 904 016 030 864Properties of molded she t:

TS (kg. 'mm. 5. 5.5 5.6 5.5 5.7 5.6 5.6

[S (kg.-cm.) 7. l6. 3 22 26 24 23 21 Percent transmission 0. 70. 1 79. 578. 6 78. 1 78. 6 81. 0

Ti C.) 1 168. 5 167.11 168. 3 168. 7 160. 2 166. 8

Gear oven stability (min.).. 130 130 125 130 125 130 EXAMPLE 8 soEXAMPLE 10 Run N o. 2 of Example 1 was repeated with use of 1.5 parts ofpoly-l-butene oxide having an intrinsic viscosity [1;] of 1.7 as theoil-soluble polyalkylene oxide. The polymerization was conducted at 53C.for 14 hoursby initially charging 69.0 parts of VCM and 5.5 parts ofpropylene and feeding 25.0 parts of VCM during the polymerization. Thusthere was obtained a graft polymer having an apparent degree ofpolymerization of 815 in a yield of 76.5 percent. The properties of asheet shaped from this polymer in the same manner as in Example 1 wereas follows: 18 of 15.1 kg-cm, TS of 5.1 kg/mm, Tf of 162.8C. and apercent transmission of 81 .3%.

EXAMPLE 9 The emulsion polymerization was conducted in the same manneras in Run No. 3 of Example 1 except that MS and Liponoy NCA werereplaced by 5.0 parts of polymerization conditions were modified asshown in Table 8.

Physical properties of sample sheets shaped from the resulting polymersare shown in Table 8, and the values of the impact strength were plottedto obtain curve c in FIG. 1.

COMPARATIVE EXAMPLE 2 Run No. 7 of Example 1 was repeated by using avinyl monomer indicated in Table 9 instead of propylene and conductingthe polymerization under conditions shown in Table 9. Results are alsoshown in Table 9.

7' TABLE s A Run number 2 3 4 5 6 FAQ:

ype. PPO PPO PPO PPO PPO (d1./gr.) 1. 6 2.1 3. 0 4. 0 5. 0 Amount(parts). 2. O 2. 0 2. 0 2. 0 2. 0 \"CM: Amount (parts) 96.0 96. 0 06.006.0 16. 0 Comonomer:

Type i-But i-But i-But i-But i-But i-But Amount (parts) 4. 0 4. 0 4. 04. 0 4. 0 atalyst:

Type LII L11 L11 L11 LII Amount (parts) 0.12 0.12 0.12 0.12 0.12Polymerization conditions Temperature C.) 54 54 54 54 54 Time (hr.:min.)16:00 16:00 16:00 16:00 16:00 16:00 Polymerization results:

Yield (percent) 82.1 85.5 84.0 .804 87.0 Apparent degree ofpolymerization.. 010 908 953 020 081 Properties of molded sheet:

. 5. 2 5.3 5.1 5. 2 5. 2 13.0 27 2s 80.5 81.3 80. 0 79. 2 78.6 Tr c.)164. 2 165.3 164. 7 105.6 166.3 167. 0 Gear oven stability (1nin.) 125125 120 125 120 TABLE 9 20 TABLE 10 Run N0. 1 2 3 4 Run No, l 2 3 PAOPVC Type PPO rro h red PPO F 730 730 110' -1, (dl/gr) 2.1 2.1 2.1 2.1 31 1 0 10 100 100 Amount arts) 2.0 2.0 2.0 2.0 VCM (p Type PPO PPO PPOAmount (parts) 94.0 96.0 97.0 95 .0 [n1 /s 21 Comonomer Amount (pans)2.0 3.0 2.0

Type MMA BuAc BuMal" VA Physical Properties of Molded Sheet Amount(parts) 6.0 4.0 3.0 5.0 TS (kg/mm) 5.3 4.7 5.1 Catalyst [S (kg-cm) 4.217.0 6.5

W L11 L11 L11 1.11 Percent transmission 11) 52.0 18.9 50.5 Amount (part)0.03 0.03 0.06 0.03 Gear oven stability (min) 40 30 4 PolymerizationVCM-Pr copolymer obtained in Run No. l of Table 1. ConditionsTemperature cc. 64.5 64.5 57.0 61.5 COMPARATIVE EXAMPLE 4 Time thnrnin)8:30 9:00 10:00 8:00 w= A S-hter inner capacity polymenzatron vesselYield 85" 843 792 840 enuipped with a stirrer was charged with amountsin- Apparent degree of dicated in Table 11 of pure water, MS, LiponoxNCA 970 882 864 and polypropylene oxide. The inside atmosphere of theMolded sheet polymenzation vessel was replaced by mtrogen and Eg T) 3 1then a vinyl chloride monomer in an amount indicated in Table l wasintroduced into the polymerization vesmiss ion sel. The stirnng wasconducted at 40C. for 8 hours to r stab 166-3 dissolve polypropyleneoxide into VCM. The intrinsic ity min 40 55 30 viscosity [1;] of thepolypropylene oxide used is shown n-butyl acrylate in Table l 1 dibutylmaleate 45 After completion of the polymerization, the unreactedmonomers were purged, and the polymer slurry COMPARATIVE EXAMPLE 3 waswithdrawn, filtered and dr1ed to obtain a wh1te Sheets were prepared bymechanically blending polyvinyl chloride and polypropylene oxide byrollmilling in accordance with the recipe for the modified, hard andtransparent product shown in Table A above.

Properties of the polymers used and results of tests of the sheets areshown in Table 10.

powder of a vinyl chloride graft polymer. The powder was blended inaccordance with the recipe shown in Table B, and the modified, hard andtransparent product was roll-milled and pressed into a sheet underconditions indicated in Table B, which was then subjected to the impacttest. Results are shown in Table 12, and were plotted to obtain curvesp, q and r in FIGS. 1 to 3, respectively.

TABLE 11 PPO lure Liponox Impact water '1" CM iv] MS NCA strength Runnumber (parts) (ports) (IL/gr. lurts (parts) (part) (km-cm.)

l. 200 94. 5 0. 5 2. 0 0.10 U. 02 0. 8 2 200 94. 5 l. 6 2. 0 (I. 10 0.02 ll. 0 3 200 04. 5 L. 1 2. 0 0. 10 0. 02 17. 0 4 200 04. 5 3. 0 .2. 00. 1O 0. 02 19.3 5.. 200 (14.5 4. 0 2. 0 0.10 0. 02 21. 4 fi 200 01. 55. 0 2. 0 0.10 0. 02 21. 5 7 .200 04. 5 0. 5 1. 5 0. 1O 0. 02 5. l 8 200.04. 5 1. 0 1. 5 0.10 0. 02 14. 4 L 200 04. 5 3. 5 1. 5 0.10 0. 02 1G. 010-. 200 04. 5 5. 0 l. 5 0. 10 0. 02 15. d 11.-. 200 04.5 0.5 1.0 0.100.02 5.2 12. 200 04. 5 2.1 1. 0 0.10 (l. 0;! 0. 8 13.. 200 04. 5 3. 51.0 0. 10 0. 0! l1. 1 14.. 200 514. 5 l. 5 1. 0 0. 10 0. 0. 10.0

EXAMPLE 11 The influences of the molar ratio of propylene to VCM wereinvestigated by employing the same operational procedure as adopted inExample I. The runs were conducted with use of 0.5 part of polyvinylalcohol instead of Liponox NCA and MS. Proportions of materials used,polymerization conditions and physical properties of the resulting graftpolymers are shown in Table 12. On the measurement of the gear ovenstability in Runs Nos. 4 and 5, the test piecescould not be self-hold bydraw-down at 180C. Thus the test pieaces were inevitably placedhorizontally on small glass plates set on a rotating ring of a gear oventester.

Data of the impact strength and the tensile strength shown in Table 12were plotted to obtain curves A and B in FIG. 4.

TABLE 12 Run No. l 2 3 4 5 PAO Type PPO PPO PPO PPO PPO [7 (dl/gr) 2.92.9 2.9 2.9 2.9 Amount (parts) 2.0 2.0 2.0 2.0 2.0 VCM Amount (parts)100 97.3 94.5 89.4 85.0 Comonomer Type Pr Pr Pr Pr Amount (parts) 2.75.5 10.6 15.0 Catalyst Type LII L11 L11 LII LII LPO Amount (part) 0.0450.08 0.12 0.20 0.20

0.015 Polymerization Conditions Temperature (C.) 66 54 51 48 48 Time(hrzmin) 5 I2 18 22 22 Polymerization Results Yield (51) 83.0 82.5 80.772.1 58.2 Apparent degree of polymerization 920 935 865 693 572Properties of Molded Sheet TS (kg/mm) 5.4 5.5 5.6 5.4 5.0 lS (kg-cm) 2132 34 26 11 Percent transmission (70) 72.1 77.4 79.7 80.3 81.0 Tf (C.)183.5 169.6 167 154.2 146.3 Gear oven stability (min) 55 125 130 I25120' the measurement was conducted by placing the sample on a glassplate horizontally set.

Curve a vinyl chloride (98.2) ethylene (1.8)

Curve b vinyl chloride (95) propylene (5) Curve vinyl chloride (96)l-butene (4) Curve p vinyl chloride (100) Curves d, e and q in FIG. 2are similar to curves given in FIG. 1 and relate to polymer compositionsobtained by employing 1.5 parts by weight of polypropylene oxide (curvesd and q) or a copolymer of propylene oxide and l-butene (curve e) as thetrunk polymer. The monomers used are as follows (parenthesized valueindicate the weight percentile ratio of each monomer in the monomericmixture used) Monomer(s) used Curve d vinyl chloride (94) isobutene (6)Curve e vinyl chloride (94.5) propylene (5.5)

Curveq vinyl chloride(l00) Curvesfand r given in FIG. 3 are similar tothose given in FIGS. 1 and 2 and relate to polymer compositions obtainedby using 1 part by weight of polypropylene oxide (curve r) and acopolymer of propylene oxide and epichlorohydrin (curve f) as the trunkpolymer. The monomers used are as follows (parenthesized value indicatethe weight percentile ratio of each monomer in the monomeric mixture)Curve f vinyl chloride (94.5-95) propylene Curve r vinyl chloride As isseen from the foregoing, each of curves p, q and r in FIGS. 1 to 3relates to a comparative polymer composition obtained by using vinylchloride alone as monomer.

When comparison of curves a, b and c with curve p in FIG. 1, curves dand e with curve q in FIG. 2 or of curve fwith curve r in FIG. 3 ismade, it will readily be understood that polymer compositions obtainedby graft polymerizing a monomeric mixture of vinyl chloride and a-olefinselected from ethylene, propylene, l-butene and isobutene to anoil-soluble polyalkylene oxide as the trunk polymer in accordance withthe process of this invention have a higher impact strength than polymercompositions obtained by grafting vinyl chloride alone to a polyalkyleneoxideas the trunk polymer, and that when the intrinsic viscosity [1;] ofthe polyalkylene oxide is within a range of from 1.3 to 4.5, especiallyfrom 1.5 to 4, there are obtained polymer compositions having goodproperties.

FIG. 4 indicates curves drawn by plotting data given in Table 12. Theleft ordinate designates the impact strength of the resulting polymercomposition obtained in Example I 1 (curve A) and the right ordinatedesignates the tensile strength ofthe resulting polymer composition(curve B), whereas the abscissa indicates the weight percentile ratio ofpropylene used as the aolefin in the monomeric mixture. From thesecurves it will readily be understood that when propylene as the a-olefinis used in an amount specified in the invention, namely 0.5 10 percentby weight, preferably 2 9 percent by weight, there can be obtained avinyl chloride polymer composition having high impact strength andtensile strength.

What we claim is:

l. A process for the preparation of a vinylchloride I polymercomposition having an improved impact strength, which comprises (a)dissolving an oil-soluble polyalkylene oxide having an intrinsicviscosity [1,], measured in benzene at 35C., of from 1.3 to 4.5 and.

selected from the group consisting of polypropylene oxide, polyl-butylene oxide, a copolymer of propylene oxide and l-butene oxide and aco-polymer of an alkylene oxide selected from propylene oxide andl-butene oxide with epichlorohydrin, in a monomeric mixture consistingof 99.5 90 parts of a vinyl chloride monomer and 0.5 10 parts of acomonomer selected from the group consisting of ethylene, propylene,l-butene and isobutene compounds, the amount of said oilsolublepolyalkylene oxide being 0.5 5 percent by weight based on the monomericmixture, (b) emulsifying or suspending the resulting solution in water,(c) polymerizing the emulsified or suspended solution at a temperatureof 30 80C. in the presence of 0.01 5

a vinyl chloride polymer and 2 9 parts of a comonomer selected from thegroup consisting of ethylene, propylene, l-butene and isobutene.

4. A process as set forth in claim 1, where-in the oilsolublepolyalkylene oxide is dissolved in the monomeric mixture in an amount ofI 3.5 percent by weight based on the monomeric mixture.

2. A process as set forth in claim 1, wherein the oil-solublepolyalkylene oxide has an intrinsic viscosity ( eta ), measured inbenzene at 35*C., of from 1.5 to
 4. 3. A process as set forth in claim1, wherein the monomeric mixture is one consisting of 98 - 91 parts of avinyl chloride polymer and 2 - 9 parts of a comonomer selected from thegroup consisting of ethylene, propylene, 1-butene and isobutene.
 4. Aprocess as set forth in claim 1, wherein the oil-soluble polyalkyleneoxide is dissolved in the monomeric mixture in an amount of 1 - 3.5percent by weight based on the monomeric mixture.